wasn’t sure if I was overreacting feeling annoyed about it
Over-reacting is an action. If you set all your partner's clothes on fire and change the locks whilst he's out, you are over-reacting to your feeling, but having the feeling (or any other feeling at all) isn't 'over-reacting. Your feelings are an expression of who you are, and just like you might like hang gliding but hate golf, or you might like crisps but hate ice cream, your feelings are you, and never 'over' or 'under' anything.
Calmly stating your feelings is never over-reacting.
I just said today that it wasn’t necessary and just caused a bad atmosphere which could have been avoided thinking he’d agree but he stands by his actions and I now think that I’m more annoyed if that makes sense
What you did today was told him what was right and wrong, which isn't respectful. What's right for one person isn't necessarily right for another, and it's respectful to offer some understanding of each other's point of view. 'I felt annoyed when you did xyz, because I feel that there might have been better ways of going about it' would have been the healthy, respectful approach. You can't tell another adult that they're 'wrong', especially not in a situation like this, where there are a billion variables. You're not in charge of him. You can only really offer your feelings, and hope that he will respect them if the situation comes up again.